Proposed work involves in vitro (isolated, mounted corneal membranes) and in vivo (intact or whole, unanesthetized) corneal transport studies on a series of homologous model compounds (the n-alkyl p-aminobenzoate esters), on selected steroids, and on selected agents used in glaucoma. A primary aim of the proposed work is to express corneal drug transport using a physical model approach in terms of physicochemical drug properties (such as solubility, partitioning behavior and permeability) and corneal membrane characteristics (such as membrane resistance, thickness, and lipid/non-lipid characteristics). Intended utilization of the resulting corneal absorption or corneal transport models involves a priori knowledge of permeation as a function of drug structure for the purpose of design and development of a new drug entities and prodrugs and greater understanding of the mechanisms of corneal drug transport.